Field
The disclosure relates generally to Buck, Boost, and other types of DC-DC switching power converters, achieving load regulation in the switching converters.
Description of Related Art
Because DC-DC switching converters usually need to provide a specified DC output voltage that remains within the voltage requirements of the circuits to which they are providing the voltage, they are typically designed to provide a voltage that remains within a specified voltage range over an anticipated range of load conditions. For example, a rapid increase in current drawn often causes a temporary undesired reduction in the output voltage of a switching converter. The switching converter must be designed to maintain an adequate output voltage for a specified maximum increase in current drawn. Similarly, a rapid decrease in current drawn can result in a temporary undesired increase in output voltage, which may be similarly characterized to ensure that the voltage increase does not exceed the voltage range required by the load.
One solution to the problem of regulating the output voltage in changing current conditions is to utilize Adaptive Voltage Positioning (AVP), which provides an intentionally varying output voltage for different current loads, such that the output voltage is a relatively low potential under a high current load and a relatively high potential under a no current load. A change in current load will then cause the output voltage to temporarily change in a direction that is compensated for by the variable output voltage.
Load regulation involves the ability of a system, such as a switching converter, to provide near constant voltage over a wide range of load conditions. The term may refer to a passive property that results in more or less voltage drop under various load conditions, or to the active intervention with devices for the specific purpose of adjusting the voltage.
FIG. 1 is a timing diagram illustrating the output voltage of a Prior Art DC-DC switching converter with a finite load regulation 120 compared with a DC-DC switching converter with no load regulation 110. The advantage of having load regulation is shown in 130, where the variation on the output voltage of the switching converter is significantly less than what it is with no regulation.